Adjustable jack



Dec. '16, 1930. l c. ca BoUDl-:TTE 1,785,069

ADJUSTABLE JACK Filed April 16. 192B 7@ A@ ff www.

Patented Dec. 16, 1930 CORNELIUS G.

BoUDE'r'rE, or cLAmIMoN'r, NEW HAMPSHIRE, AssIc'Noa rr'o SULLIVANMACHINERY COMPANY, A CORPORATION OF MASSACHUSETTS ADJUSTABLE JACK j YApplication led April 16, 1928. j' Serial No. 270,456.

This invention relates to adjustable jacks and more particularly to anadjustable roof jack especially adapted to use in mines.

An object of this invention is to provide an improved adjustable jack.Another object is to provide an improved adjustable jack which may beset up and taken down quickly and with facility. Another object is toprovide an'improved adjustable jack having improved adjusting means ofsimple yet rugged construction and adapted to be .manufactured atrelatively small expense.

These and other objects of this invention will, however, hereinaftermore fully appear as the description proceeds.

In the accompanying drawing. there is shown for purposes of illustrationone form which the invention may assume in practice.

In thisdrawingf- Fig. 1 is a side elevational view of the improvedadjustable jack, parts being omitted to facilitate illustration.

Fi 2 is a longitudinally extending sectiona view taken substantially online 2-2 of Fig. 1.

Fig. 3 is a perspective view of one of the pawl adjusting levers. j

Fig. 4 is a perspective view of one of the pawls. a 1

Fi 5 is an elevational view illustrating the jack set up inoperativeposition in a mine. f c

Inv this illustrative construction there 1s shown a jack 1 comprising amain tubular body portion 2 carrying at its upper end a member 3 havingpivotally connected thereto at 4 an ad'ustable abutmentr or supportengaging mem er 5 having serrations on its upper surface adapted toengage suitable blocking or the mine roof. As sho'wn, iixed as by rivetsor other suitable attaching means adjacent the lower end of the tubularjack body. 2 is alianged collaror coupling 6, the flange of whichrotatably supports a casing or housing 7. This housing has a centralopening 8 within` which the lower end of the jack bodyprojects as shownin Fig. 2. Pivotally mounted on pins 9 carried'by the housing 7 arepawls or dogs lOengagelable with helically formed teeth 11 on an axiallymovable adjusting screw 12 extendingvthrough the central opening in thehousing and telescopically arranged within the tubular jack body 2. Thisscrew is provided at its outer or: lower end with an abutment engagingmember or foot piece 13-having spaced points `14 for maintaining theadjusting screw 12 against rotative movement during adjustment of thejack. This foot piece is engageable with suitable blocking or the mineloor. i

As illustrated, arranged within the housing 7 are coil springs 15 actingon the pawls 10 `for yieldably maintaining the latter in engagementlwith the teethV of the adjusting screw. Suitable adjustable lugs orfollowers 16 are threaded intothe ousing and are adjustable to Vvary thetension of the coil springs. In accordance with this invention the pins9 also have pivotally mounted thereon levers 17 projecting laterallyYthrough these lugs each have oppositely located abutment surfaces 21and 22. The pawls 10 have similar abutment surfaces 23 and 24 formed bycutting away a portion of their bearing supports. It W1ll thus be seenthat when the levers 17 are in the positionindicated in full lines inFig. 2 the abutment surfaces 21 on the levers areA in engagementwith theabutment surfacesl 24 on Athe pawls 10, while when the levers are in thedotted line positon in that ligure the surfaces 22 and 23 on the leversand pawls respectively are in engagement. It will furtherv be seen thatwhen the levers 17 are in the yfull line position shown in Fig.

.2 and are pressed inwardly toward one an- ,the operator first placesthe jack in the position shown in Fig. 5 and then presses inwardly onthe levers 17 releasing the pawls 10 from engagement with the teeth on.the adjacklbody and the justing screw 12 thereby permitting the latterto slide downwardly until the foot piece 13 engages the blocking or themine floor, the levers thereafter being released and the pawlsautomatically maintaining the jack in position. The operator then swingsthe levers 17 downwardly into the dotted line position shown in Fig. 2and as shown in full lines in Fig. 5 and then bodily rotates the housing7 relative to the tubular jack body thereby causing the pawls to act asa nut forcing the adjusting screw axially apart and as a result the jackis rigidly held in position, the pawls preventing separation between theadjusting screw and the jack body when the jack is so positioned. Whenit is desired to take down ithe jack the operator merely rotates thehousing 7 thereby loosening the jack parts and thereafter releasing thepawls from the adjusting screw permitting the latter to be slid inwardlywithin the jack body, the pawls maintaining the adjusting screw in itsretracted position.

As a result of this invention it will be noted that an improvedadjustable jack is provided which may be adjusted expeditiously and withfacility. It willfurther be noted that t-he adj ustin means for the jackis composed of a relative y few parts which are of simple yet ruggedconstruction especially adapted to withstand the severe conditions ofservice and which may be manufactured at a minimum of expense; These andother uses and advantages of this invention will be clearly apparent tothose skilled in this art.

While I have in this application specifically described one form whichmy invention may assume in practice, it will be understood that thisform is shown for purposes of illustration and that the invention may bemodified and embodied in various other forms without departing from itsspirit or the scope of the appended claims.

WVhat I claim as new and desire to secure by Letters Patent is:

1. An adjustable jack comprising a body member carrying an abutmentengaging member, a plurality of pawls carried by said body member, ahelical screw arranged to telescope within said body member, springmeans normally tending to hold said pawls in engagement with the threadson said helical screw, said pawls having means adapted to cooperate withsaid threads for effecting relative longitudinal movement of said bodymember and screw upon rotation of said pawls around said screw, andhandle means adjustable relative to said pawls and movable into oneposition to effect release of said pawls from said threads to permitfree collapsing of said jack, said handle means also being adjustable toanother position wherein they project laterally to serve as leverageattainlng means for rotating said pawls around said screw.

rnection therewith handle members having a lost motion connection withsaid pawls adapted when swung toward said body member to engage saidpawls and to move them out of engagement with said threads to permitfree collapsing of said jack, said lost motion connection permittingsaid handle members to be swung to a position substantially at rightangles to said screw to serve as means whereby the pawls may be rotatedabout said screw to effect adjustment of said jack.

3. An adjustable jack comprising a tubular body carrying an abutmentengaging member, a helical screw telescoping therewith, a housingrotatably connected to said body member and surrounding said screw, apair of pawls pivotally carried in said housing, a pair of springsacting on said pawls normally tending to hold them in engagement withthe threads on said helical screw whereb rotation of said housin andpawls aroundy said screw will effect adjustment of said jack, and a pairof handle members pivotall mounted on the same aXis as said pawls andhaving a lost motion conwhereb they may be moved to one position to eect release of the pawls from said threads and to another position atright angles to said screw to serve as means for rotating the housingand pawls.

4. An adjustable jack comprising atubular body member carrying abutmentengaging means, a helical screw arranged to telescope within said bodymember, adjustable elements adapted to engage with the threads on saidscrew for effecting relative longitudinal adjustment between said bodymember and screw upon rotation of said elements around said screw, andhandle means for adjusting said thread engaging elements and movableinto one position to effect release of said thread engaging elements andinto another position to provide lever means for rotating said threadengaging elements around said screw, said handle means in said lastmentioned position permitting enga cment of said thread engagingelements with the threads of said screw.

5. An adjustable jack comprising a hollow body member carrying anabutment engaging means, a support rotatably mounted on said bodymember, a helicalscrew arranged to telescope within said body member,elements adjustably mounted on said rotatable support and movable intoand out of engagement with the threads on said screw, and handle meansadjustably mounted on said support and adjustable into a position formoving said thread engaging elements out of engagement with saidthreadslt'o permit free collapsing of. the -ack, said handle means alsobeing adjusta le into a `position `to move said thread engagin elementsinto engagement with said threa s, said handle means being operative toeffect rotation of said support relative to said body member to movesaid thread engaging elements about said screw toV effect relativelongitudinal adjustment of the body member andscrew.

6.` An adjustable jack comprising a hollow body member carrying anabutment engaging means', a su port rotatably mounted on said body memIer, a helical screw arranged to telescope within said body member.,pawls carried by said rotatable supportv and engageable with the threadsof said helical screw, said pawls being adapted to cooperate with saidthreadsfor leffecting relative longitudinal movement of said body memberand screw u on rotation of said support relative to sai body member,said support being rotatable to effect movement of said pawls aroundsaid screw, and handle means for releasing said pawls from engagementwith said threads to permit free collapsing of said jack and forrotating said support relative to saidv body member to effect rotationofsaid pawls around said screw. j

7 An adjustable jack comprising a hollow body member, a su portrotatably mounted on said body mem -r,`"a helical screw arranged totelescope within said body member, pawls pivotally mounted on saidrotatab e support and adapted to cooperatewith the threads of saidhelical screw, andI meansy for rotating said support relative to saidbody member to effect movement of said pawls around said screw foradjusting said screw longitudinally relative to said body memberincluding handle members pivotally connected to said support about axescoincident with the pawl axes and swingable relative to said pawls, saidhandle members also being operative to effect release of said pawls thevthreads of said screw to permit free colla sing of said jack.

8. An adjustable roof jack comprising a tubular body -member, anadjusting screw telescopically received in said body member, said bodymember and screw having abutment engaging members normally preventingrotation of` said body member and screw when the jack is in operativeposition, and means for elfectin relative axial adjustment of said bodymem er and screw to move said abutment engaging members apart toposition the jack, and including a rotatable membei` carried by saidbody member, an element carried by and adjustable relative to said roftatable member and forming a nut engageable with the threads of saidscrew, and means for adjusting said nut forming .elementmto and out ofitsthread 'engaging position while said screw remains stationary withrefspect thereto, and for rotating said rotatable member relative tosaid body member when.

said-nut forming element is in its thread entubular bo y member, anadusting screw,l

telescopically received in sai body member, said body member and screwhaving abutment engaging members normally preventing rotation of vsaidbody member and screw when the jack is in operative osition,

ment of said body mem er and screw to move said abutment engagingmembers apart to position the jack, and including a rotatable membercarried by said body member, an element carried by and adjustablerelative Vto and means for electin relative axia adj ustsaid rotatablemember and forming a nut env gageable with the threads of said screw,and means for yadjusting said nut forming element into and out of itsthread engaging position while said screw remains stationary withrespect thereto, and for rotating said rotatable m'ember relative tosaid body member when said nut forming element is in its thread engagingposition to et'ect relative axial adjustment of said body member and`screw, said screw and body member when said nut forming element isreleased from the threads of said screw having free telescopic' movementto rmit collapsing lof the jack, and said nut orming element engagingthe threads 'of said screw to form a` lock to hold said screw in itscollapsed position.

In testimony whereof I aiiix my signature.

CORNELIUS G. BOUDETTE.

